VO₂ Max & Resting Metabolic Rate
VO₂ Max • measured directly • ~20 min test
RMR • indirect calorimetry • 10–15 min
Results • same day
Why We Measure It
The American Heart Association has recommended treating cardiorespiratory fitness as a vital sign since 2016. Almost no primary care practice measures it.
VO₂ max is a whole-system number. It reflects how well your heart moves blood, how efficiently your lungs load it with oxygen, how much of it your muscles can extract, and how well your mitochondria use it once it arrives. No single lab value integrates that much physiology, which is why it tracks mortality better than any of them individually.
It also declines on a predictable curve — roughly 10% per decade after 30 in sedentary adults, and faster after 50. That decline is the reason the number matters clinically rather than athletically. Aerobic capacity is what determines whether you can carry groceries up stairs at 80, and it is trainable at every age we treat.
Resting metabolic rate answers a different question: how much energy your body spends doing nothing. It is the number a nutrition plan should be built on, and predictive formulas get it wrong in individuals often enough to matter. If you are trying to lose fat without losing muscle, an estimated number is the wrong foundation.
What We Measure
The Appointment
The appointment runs an hour and covers both tests. The VO₂ portion is a graded exercise test on a treadmill or a bike: it starts easy, gets harder every few minutes, and ends when you reach your true maximum rather than a predicted one — usually around 20 minutes in. You will be working hard at the end. That is the point, and staff are with you throughout.
The RMR measurement takes 10 to 15 minutes. You lie still, breathing normally through a mask, while we measure the oxygen you consume and the carbon dioxide you produce. Nothing about it is strenuous — most patients find it restful.
You do not wait for results. Your numbers are explained the same day, in the same visit.
Interpretation
Any lab can hand you a number. The value is in what gets prescribed off the back of it.
The result is read against your percentile, your history, and the rest of your panel — then a target is set, and the training that reaches it. In practice that usually means a specific weekly volume at low intensity, a smaller dose of harder work, and a retest date. Zones come from your measured response, so the prescription is specific to your physiology rather than a category you were sorted into.
RMR does separate work. It sets the floor on any deficit we prescribe, which is how we avoid the pattern that undoes most weight loss — cutting calories far enough that the body gives up lean tissue alongside fat. Paired with a DEXA scan, we can see whether what you are losing is the thing you wanted to lose.
VO₂ max is System 2 of the Peak Longevity Six. It is measured alongside the other five, because a strong number here does not compensate for a weak one elsewhere.
Retest cadence
We do not test more often than quarterly unless there is a clinical reason to — the biology does not move fast enough for it to tell you anything.
Pricing
VO₂ max testing
$150
Resting metabolic rate
$50
VO₂ max + RMR + DEXA together
$325
Both tests are included in Peak Longevity and Peak Elite, and repeated on the cadence your protocol calls for. Peak Foundations patients can add either at the à la carte price. Most patients use FSA or HSA funds.
Testing is done in our Meridian office, and patients travel to it from across Boise, Meridian and Eagle. No referral is required.
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